There exists technology that uses physical resources of a physical server to run a virtual machine (VM). Such a physical server may be referred to as a VM host, while such a virtual machine may be referred to as a VM guest in contraposition with the VM host, for example.
There exists migration technology that moves a VM guest running on a VM host to another VM host. For example, in the case of stopping or rebooting a VM host for maintenance or another reason, a VM guest running on the VM host targeted for maintenance is moved to a different VM host, and the task executed by the VM guest is made to continue.
Related techniques are disclosed in, for example, Japanese Laid-open Patent Publication No. 2007-179100 and International Publication Pamphlet No. WO 2004/086246.
However, with the above technology, in some cases it takes time for the VM guest to resume a process after migration.
For example, after starting migration, a management device suspends a process of the VM guest to be migrated, and transfers data used by the VM guest for that process from the source VM host to the destination VM host. Even if migration has completed, the VM guest may be unable to resume the process until completion of the data transfer. In the case of transferring a large amount of data, it may take time until the process is resumed.
The VM guest may restart the suspended process all over from the beginning after migration is completed. However, depending on factors such as the data transfer rate and the remaining processing load, waiting for the data transfer to complete and resuming the process rather than restarting all over from the beginning may enable earlier completion of the overall process in some cases.